1. Field of the Invention
The invention relates generally to fault-tolerant distributed processing systems and, in particular, to failover mechanisms for the fault tolerant systems.
2. Background Information
Distributed processing systems utilize applications residing on many servers. The applications communicate with one another while performing various tasks, such that processing data may involve several applications that must collaborate at various times. The processing involved in the tasks relies on the various applications being available at the appropriate times to process and provide the necessary data. The number of applications involved in a given task depends on the particular task and on the magnitude of the processing to be performed.
To ensure the availability of critical operations, fault tolerance may be added to the system. Depending on the applications, prior systems may require that processing operations take place on duplicate servers. In such systems the duplicate operations may be burdensome to the system and/or may slow the overall system operations. In other known systems, each processing node or server keeps track of the status of the other servers in order to determine when a failover between a primary server and the backup server that shares access to the same data files should occur. A problem with such systems is that the failover operations must be essentially re-configured when, for example, new servers are included in the system. What is needed is a failover, or change-over, mechanism that is readily scalable.